Carbureted Engine

Fig. 44 Ignition timing control system:

This system, Fig. 44, provides additional vacuum advance to aid in cold engine driveability and emission control. The distributor has two separate vacuum advance diaphragms. Diaphragm A operates on manifold vacuum. Diaphragm B also operates on manifold vacuum but has a control device in the line. On CRX 1500HF Federal models, when the cold advance solenoid valve is activated by the control unit and radiator fan control unit, it sends manifold vacuum to diaphragm B through check valve E to improve engine performance. On all models except CRX 1500HF Federal, when engine coolant temperature is below the set temperature of thermovalve B, thermovalve sends manifold vacuum to Diaphragm B through check valve E to improve cold engine performance.